A relative had brain surgery for a tumor, and if I'm remembering what she said from fifteen years ago correctly she said the anesthesia shot hurt, than the rest was more a relief than anything as the tumor had been applying constant pressure for years.
Wait, what?
(I am even hesitant to ask as I'm not sure I'm ready to hear the answer, whatever it might be.)
Apparently, the wrestlers cut themselves on their scalp / forehead some time into a match to make the match look more intense, with the blood from their head mixing with sweat and dripping down...
A 17 year old kid was even hospitalized due to blood loss from it.
https://en.m.wikipedia.org/wiki/Blading_(professional_wrestl...
Bleeding stopped in a minute or two just by holding a towel on the scratched part.
I imagine it might be similar to having a cavity filled.
Obviously there are some things that would be different. For example a big issue is you’d want to use non-toxic lubricant on all the parts. Not sure what non-toxic means but I’m sure there is something (vegetable oil? Silicone?)
You’d also want to make sure it won’t fling off tiny metal or plastic shards from the tool. Don’t want that to get into the body. You’d probably have to seal up any ventilation openings in such a way that crap couldn’t escape.
I’m sure mechanically you’d want it to be as tight of tolerance as you could get away with—you probably don’t want a lot of slop when cutting open some dudes skull. Vibration and such probably play into that tolerance bit…
Of course it could just literally be a rebranded Ryobi or something for all I know. But I’m pretty sure it isn’t. Too many additional requirements means it is probably something slightly fancier.
Not long ago I designed a set of bone taps and drills along with a bunch of related instruments and they were designed and made not much differently than high end tools for metal or woodworking.